Smoke detector



FIG. 1 is a perspective view of a smoke detector showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left end view with the right end view being a mirror image thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom view thereof. 

The ornamental design for a smoke detector, as shown and described. 